1. Field of the Invention
The present invention relates to a passive element, such as a resister element, condenser element and coil element, a passive element composite component in which plural passive elements are connected with each other, a substrate having a built-in passive element and a composite wiring substrate which are used in electric, electronic and communication fields.
2. Background Art
Along with the recent development of portable and multifunctional electronic devices, electronic devices have been miniaturized. Because in the case of, particularly, high performance electronic devices such as portable telephones and wearable computers, a multifunctional electronic circuit is stored in a case having a small capacity, it is inevitable to accomplish high density packaging. This is the reason why not only the miniaturization of electronic components but also technologies concerning wiring boards formed with fine wiring are essential for high density packaging.
In, particularly, a wiring substrate used in a radio module, it is necessary to use a low-dielectric substrate in a usual wiring part to treat high speed signals whereas it is rather effective to use a high-dielectric substrate in an antenna part. Therefore, there is an increasing need of forming regions each having a different electromagnetic characteristics on a single substrate. However, it is difficult to form the low-dielectric component and the high-dielectric component separately on a single wiring substrate.
In this situation, substrates designed to have a multilayer structure by laminating a plurality of substrates and by binding these substrates to integrate them are known (see the publication of JP-A-2001-15916). However, if plural substrates having different characteristics are laminated, layer peeling tends to be caused by a difference in the thermal expansion coefficient of each substrate.
Similarly, as to, also, a built-in element type wiring substrate incorporated with passive elements such as a condenser, a multilayer wiring substrate incorporated with a high-dielectric layer for forming a condenser is known (see the publication of JP-A-11-179824). However, in such a wiring substrate, layer peeling and the like are also easily caused and only a condenser is disposed on the high-dielectric layer, giving rise to the problem that it is difficult to improve packaging density.
As aforementioned, the wiring substrates having a laminate structure have the problem that layer peeling is easily caused. Also, in the case of mounting plural components which make a demand upon substrates for each different electromagnetic characteristics, on a single substrate, there is a limitation in the design of circuit arrangement, posing the problem that the efficiency of storing electronic circuits is decreased.
Moreover, in, also, a passive element electronic component having a conventional laminate structure, the miniaturization makes it difficult to maintain mechanical strength which a relatively large component originally possess, which affords the possibility that the layer peeling of the elements is caused by a thermal or mechanical shock.
As aforementioned, with regard to radio module wiring substrates and wiring substrates with a built-in passive element, multilayer wiring substrates prepared by laminating plural substrates differing in dielectric constant and the like are proposed. However, such a method as to make each layer differ in characteristics such as dielectric constant has the problem that layer peeling tends to be caused and further it is difficult to improve packaging density.
In view of this situation, it is an object of the present invention to provide a composite material, such as a passive element component and substrate with a built-in passive element, which is free from problems such as layer peeling and can accomplish high density packaging easily.
The present invention has been made to solve the above problems and made from the viewpoint based on the fact that a passive element, passive element composite component, substrate with a built-in passive element and composite wiring substrate which are free from layer peeling can be formed by filling pores in selected regions of a porous base material, in which continuous pores are formed, with a conductive material, passive element functional material, insulation material or the like.
According to a first aspect of the present invention, there is provided a passive element component comprising a conductive material region produced by filling a conductive material in two regions of a porous base material which regions are not in contact with each other and a functional region sandwiched between each conductive material region on the porous base material and prepared by filling the porous base material with a passive element functional material.
According to a second aspect of the present invention, there is provided a passive element component comprising a conductive material region and plural functional regions produced by filling each pore of a porous base material with a material having different electromagnetic characteristics, wherein;
one of the plural functional regions is a passive element functional material region which is in contact with the conductive material region, is produced by filling pores of the porous base material with a passive element functional material and constitutes a passive element together with the conductive material region; and
the other of the plural functional regions is an insulation material region which is in contact with at least one of the conductive material region and the functional material region and is produced by filling pores of the porous base material with an insulation material differing from the passive element functional material.
According to a third aspect of the present invention, there is provided a passive element component comprising a first functional region, a second functional region and a third functional region produced by filling each pore of a porous base material with a material having different electromagnetic characteristics, wherein;
the first functional region is a conductive material region produced by filling the porous base material with a conductive material;
the second functional region is a passive element functional material region which is in contact with the conductive material region, is produced by filling pores of the porous base material with a passive element functional material and constitutes a passive element in combination with the conductive material region; and
the third functional region is an insulation material region which is in contact with at least one of the conductive material region and the functional material region and is produced by filling pores of the porous base material with an insulation material differing from the passive element functional material. In the first to third aspects of the present invention, the passive element constituted of the conductive material region and the functional material region may be provided plurally.
Also, the plural passive elements are preferably separated from each other by the insulation material region.
According to a fourth aspect of the present invention, there is provided a condenser element component comprising a conductive material region produced by filling a conductive material in two regions of a porous base material which regions are not in contact with each other and a functional region sandwiched between each conductive material region on the porous base material and prepared by filling the porous base material with a high-dielectric material, a resister element component comprising a conductive material region produced by filling a conductive material in two regions of a porous base material which regions are not in contact with each other and a functional region sandwiched between each conductive material region on the porous base material and prepared by filling the porous base material with a resistant material or a coil element component comprising a conductive material region produced by filling a conductive material in two regions of a porous base material which regions are not in contact with each other and a functional region sandwiched between each conductive material region on a porous base material and prepared by filling the porous base material with a high-magnetic permeability material.
According to a fifth aspect of the present invention, there is provided a substrate with a built-in passive element, the substrate being provided with a passive element component comprising a conductive material region and plural functional regions produced by filling each pore of a porous base material with a material having different electromagnetic characteristics, wherein;
one of the plural functional regions is a passive element functional material region which is in contact with the conductive material region, is produced by filling pores of the porous base material with a passive element functional material aid constitutes a passive element in combination with the conductive material region; and
the other of the plural functional regions is an insulation material region which is in contact with at least one f the conductive material region and the functional material region and is produced by filling pores of the porous base material with an insulation material differing from the passive element functional material; or
a passive element component comprising a first functional region, a second functional region and a third functional region produced by filling each pore of a porous base material with a material having different electromagnetic characteristics, wherein;
the first functional region is a conductive material region produced by filling the porous base material with a conductive material;
the second functional region is a passive element functional material region which is in contact with the conductive material region, is produced by filling pores of the porous base material with a passive element functional material and constitutes a passive element in combination with the conductive material region; and
the third functional region is an insulation material region which is in contact with at least one of the conductive material region and the functional material region and is produced by filling pores of the porous base material with an insulation material differing from the passive element functional material; and further wiring for connecting these passive elements.
In the substrate with a built-in passive element according to the fifth aspect of the present invention, the passive element may be designed to be a condenser element produced by filling the functional region of the porous body with a high-dielectric material, a resister element produced by filling the functional region with a resistant material or a coil element produced by filling the functional region with a high-magnetic permeability material. Also, this substrate with a built-in passive element maybe provided with plural passive elements, which are connected with each other by using wiring formed by allowing a porous substrate to be impregnated with a conductive material to form an electronic circuit. Also, the substrate with a built-in passive element maybe further provided with a through-hole formed on the surface of the substrate for mounting electronic components.